On my forehead like tilakas are the five Theras:Puñña, Angulimala, Upãli, Nanda and Sivali.

The other Eighty Theras,The Victorious Disciples of the Conqueror,shining in the glory of their virtues, rest on the otherparts of my body.

The Jewel Sutta is on my front,on my right The Sutta on Loving Kindness.The Banner Sutta is on my back,on my left is The Angulimala Sutta.

The protective discourse Khanda, Mora and Atanatiya Suttas arelike the Heavenly vault.All the other Suttas are like ramparts around me.

Ever engaged in four duties, do I dwell inthe Buddha Mansion, fortified by thecommanding power of the Buddha anddecked by the wall of the Dhamma.

By the power of their infinite virtues,may all internal and external troubles come to naught withoutexception.

May all those great personages ever protectme who am dwelling in the centre of theBuddha Mansion on this earth.

Protecting myself thus in every way,overcoming all troubles by the power of the Conquerors(The Buddha, The Dhamma and The Sangha)may I defeat the hostile army of passions and live guarded byThe Sublime Dhamma!

Rain soddens what is kept wrapped up,But never soddens what is open;Uncover, then, what is concealed,Lest it be soddened by the rain.

where is this from? it seams similare to some tibetan things I have seen before?

This offering maybe right, or wrong, but it is one, the other, both, or neither!Blog,-Some Suttas Translated,Ajahn Chah."Others will misconstrue reality due to their personal perspectives, doggedly holding onto and not easily discarding them; We shall not misconstrue reality due to our own personal perspectives, nor doggedly holding onto them, but will discard them easily. This effacement shall be done."

This is a chant composed probably in Sri Lanka under Tantric influence which has later found its way to Thailand and was made popular by Somdet Toh of Wat Rakhang. It is supposed to bring protection to people and that is why it is very popular e.g. among Thai women, many of whom know it by heart and chant it every day.

Jinapañjaraṃ(22-gāthā Sinhalese version & English translation)

1.jayāsanagatā vīrājetvā māraṃ savāhiṇiṃcatusaccāmatarasaṃye piviṃsu narāsabhāSeated on the victorious seats, the heroes,Having conquered Māra with his retinue,The juice of nectar of the four truths,Those lords of men who drank,

2.taṇhaṅkarādayo buddhāaṭṭhavīsati nāyakāsabbe patiṭṭhītā tuyhaṃmatthake te munissarāThe Buddhas, Taṇhaṅkara and others,The eight and twenty leaders,All of them have stood firmly on yourHead, those chiefs of sages.

3.sire patiṭṭhitā buddhādhammo ca tava locanesaṅgho patiṭṭhito tuyhaṃure sabbaguṇākaroThe Buddhas are established on the head,And the Dhamma in your eye,The Saṅgha is established in yourChest, the source of all virtues.

5.dakkhiṇe savaṇe tuyhaṃāhuṃ ānandarāhulākassapo ca mahānāmoubho'suṃ vāmasotakeIn your right earWere Ānanda and Rāhula;Kassapa and MahānāmaWere both in your left ear.

6.kesante piṭṭhibhāgasmiṃsuriyo viya pabhaṅkaronisinno sirisampannosobhito munipuṅgavoBehind you at your hairs' end,Like the sun, the maker of light,Has sat the one possessed of fortune,Sobhita, a bull among sages.

9.sesāsīti mahātherāvijitā jinasāvakājalantā sīlatejenaaṅgamaṅgesu saṇṭhitāThe remainder of the eighty great elders,The victors, the disciples of the Jina,Shining with the power of their virtueAre settled in your various limbs.

11.khandhamoraparittañcaātānāṭiyasuttakaṃākāsacchadanaṃ āsisesā pākārasaññitāThe Khandha and Mora protectionsAnd the ĀtānāṭiyasuttaHave become a roof in the sky;The rest of the Suttas serve as ramparts.

12.jināṇābalasaṃyuttedhammapākāra'laṅkatevasato te catukiccenasadā sambuddhapañjareTo you who dwell in the fourfold duty,Ever in the mansion of the Fully Awake,Bound by the authority of the Jinas,Adorned with the ramparts of the Dhamma,

13.vātapittādisañjātābāhirajjhatt'upaddavāasesāvilayaṃ yantuanantaguṇatejasāBy the power of their limitless virtue,May outer and inner afflictionsArisen from wind, bile and other humours,And all other disturbances depart.

14.jinapañjaramajjhaṭṭhaṃviharantaṃ mahītalesadā pālentu tvaṃ sabbete mahāpurisāsabhāIn the middle of the Jinas' mansion,Living on the earth,May all those great bulls of menForever protect you.

18.saddhammapākāraparikkhito'siaṭṭhāriyā aṭṭhadisāsu hontietthantare aṭṭhanāthā bhavantiuddhaṃ vitānaṃ'va jinā ṭhitā teYou are surrounded by the ramparts of the Saddhamma,Eight Ariyans are in the eight directions,Between these are eight protectors,And above, like a canopy, stood the Jinas.

19.bhindanto mārasenaṃ tava sirasi ṭhito bodhim-āruyha satthāmoggallāno'si vāme vasati bhujataṭe dakkhiṇe sāriputtodhammo majjhe urasmiṃ viharati bhavato mokkhato morayoniṃsampatto bodhisatto caraṇayugagato bhānulok'ekanātho.Breaking asunder the army of Māra, on your head stood the Teacher, after ascending the Bodhi-seat,Moggallāna is on your left, dwelling on your arm, and Sāriputta on your right.The Dhamma dwells in the middle of your chest.The Bodhisatta, having gone from Mokkha to Morayoni, has gone to your two feet, that sole protector of the world.

20.sabbāvamaṅgalam-upaddavadunnimittaṃsabbītirogagahadosam-asesanindāsabb'antarāyabhayadussupinaṃ akantaṃbuddhānubhāvapavarena payātu nāsaṃ.All inauspices, afflictions, ill omens,All calamities, illnesses, planetary faults, and blame,All obstacles, dangers, bad dreams, and the unpleasant,Through the power of the Buddha's excellence may these all disappear!

21.sabbāvamaṅgalam-upaddavadunnimittaṃsabbītirogagahadosam-asesanindāsabb'antarāyabhayadussupinaṃ akantaṃdhammānubhāvapavarena payātu nāsaṃ.All inauspices, afflictions, ill omens,All calamities, illnesses, planetary faults, and blame,All obstacles, dangers, bad dreams, and the unpleasant,Through the power of the Dhamma's excellence may these all disappear!

22.sabbāvamaṅgalam-upaddavadunnimittaṃsabbītirogagahadosam-asesanindāsabb'antarāyabhayadussupinaṃ akantaṃsaṅghānubhāvapavarena payātu nāsaṃ.All inauspices, afflictions, ill omens,All calamities, illnesses, planetary faults, and blame,All obstacles, dangers, bad dreams, and the unpleasant,Through the power of the Saṅgha's excellence may these all disappear!

Could you say more about this tantric influence? Interestingly, the gatha also is found here and here (will open .pdf doc). I encountered it in a booklet titled "Daily Buddhist Devotions" by Ven. K Sri Dhammananda, which was given to me by a venerable monk from Sri Lanka, who has my deepest respect and gratitude. The booklet also contains the Ratana Sutta and the Mangala Sutta (in Pali and English), among other traditional verses, salutations and gathas. I'm amazed at how these seemingly simple texts continue to reveal layer upon layer of meaning, and I wonder why they don't receive more attention than they do among those of us who like to discuss these things on the Internet.

May the merit and virtue accrued from this work adorn Amitabha Buddha's Pure Land, repay the four great kindnesses above, and relieve the suffering of those on the three paths below.

May those who see or hear of these efforts generate Bodhi-mind, spend their lives devoted to the Buddha Dharma, and finally be report together in the Land of Ultimate Bliss. Homage to Amita Buddha!

NAMO AMITABHA

Taken together with Manapa's comments and the thoughts about tantric influence, this looks like a case study in cross-pollination of various Buddhist influences. Maybe we have more in common than we sometimes imagine?

Rain soddens what is kept wrapped up,But never soddens what is open;Uncover, then, what is concealed,Lest it be soddened by the rain.

Definitely. There was quite a lot of Mahayana and Tantrayana presence in medieval Sri Lanka and also the other Theravada countries, as is evident from archaeological evidence. Especially when it comes to Puja and other rituals connected with Buddharupas, this certainly is not "pure Theravada" (= early Buddhism).